Retroreflective marking material, usually white or an alternating red-white pattern, that is applied to the rear and sides of vehicles to create visual contrast and clearly delineate vehicle size.

A designated (posted) speed of 45 mph or above.

While defined by each Agency, typically identified as average daily traffic (ADT) volumes greater than 2000 vehicles per day.

A motor vehicle carrying at least two or more persons, including carpools, vanpools, and buses. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

"Personal protective safety clothing intended to provide conspicuity during both daytime and nighttime usage" [ANSI/ISEA 1999].

A power-operated traffic control device by which traffic is warned or directed to take some specific action. These devices do not include power-operated signs, steadily-illuminated pavement markers, warning lights (see Section 6F.83), or steady burning electric lamps.

The general area where a highway and a light rail transit route cross at the same level, within which are included the light rail transit tracks, highway, and traffic control devices for traffic traversing that area. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

The general area where a highway and a railroad cross at the same level, within which are included the railroad tracks, highway, and traffic control devices for highway traffic traversing that area. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

high occupancy tolls MUTCD 2009 Edition with May 2012 Revisions 1 and 2

FHWA's Office of Transportation Management MUTCD 2009 Edition with May 2012 Revisions 1 and 2

FHWA's Office of Transportation Operations MUTCD 2009 Edition with May 2012 Revisions 1 and 2

high-occupancy vehicle MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Any preferential lane designated for exclusive use by high-occupancy vehicles for all or part of a day including a designated lane on a freeway, other highway, street, or independent roadway on a separate right-of-way. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

A special type of beacon that is intentionally placed in a dark mode (no indications displayed) between periods of operation and, when operated, displays both steady and flashing traffic control signal indications. MUTCD 2009 Edition with May 2012 Revisions 1 and 2